Railway-traffic-controlling apparatus



July 3, 1928.

H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Oct. 7, 1925 a Sheets-Sheet U N W a N J m R. a R A .m m F. w F w W M A W K R g m I Q LP m h A Av b% M? A A x M l\u- M m cm W\ QM NN A m 3 WWWQM A A v W Q W A MW A w ww J 6N QN N w\wd.

M J MN July 3, 1928.

H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Oct. 7, 195 s Sheets-Sheet 2 Q m M $131M w v INVENTOR'.

BY agv/im/ xg #4,; ATT QRNEY H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Oct. 1925 July 3, 1928.

, Y E V N m BN M M m T T i M lw M. Q 5 H \WV \wmflm J VV\ v mv 5 5? w a m MN W DDN WW UN wm mm ww mmm mm Q NW 6% Wm \wm mm 9m 6%. NW. mw MJQU WM. w \WM ON m? RV rwl wm qmdL mN MM PW 06 m V I Y T. NM NV mg 3v. PW aw R i Patented July 3, 1928.

re see H :HERBEBT A. WAL E orirne wobnsso dnefl :P W L A M AS NQM -Q E UNION SWITCHW& SIGNAL CQMPANYQIOFSSWINSSMALE, rEunsxLvauiA, A 003mm- TIQN OF PENNSYLVANIA. I

namwanram econraonnnge i rmaarus.

Application flled October 7, Serial No 609(59.

My invention relates to railway trafiic controlling apparatus, and particularly toapparatus ofthe type comprising tram carried governing mechanism controlledby code impulse coin bina tions received from thetrackway. r i In apparatus ofthis type it has been suggested to supply thev trackwaywith difierent code impulse combinations, and to provide trains with governing mechanism selectively responsive to such codes. One feature "of my present invention p the provision, n apparatus of such'characteryof train carried governing mechanism comprising slow a'ctmechanism suitable. for cooperation with the traelrway apparatus illustrated in F ig.1-;and also embodying my invention' Figs; "3,4, 5 and 6 are 'views'showingmodifiedforms of the apparatus illustrated in {Fig.fQ and also embodying my invention Similar reference characters refer to 'similar parts in each of the several views. Referring firstto 'Fig. 1, the reference characters 1 and 1 designatethe track rails p y K just described for' relay Q Relays Q'jare of a stretch of railway track otter-Which trafiic normallyy noves, in the direction indicated by the arrow. These track rails are divided, by means of insulated joints 2, into a plurality of SLICCQSSlVB track sections B-C, etc. Each such track section is providcd with track relay designated by mt he reference character R with an apprepriate distinguishing of the associated section. Each trackfsection is also provided with a "trackftr ansformer designated by the reference character T with an exponent correspondinglito the location and having a secondary 4 connected across, the rails adjacent. theexit end of the corresponding section. Associatedwith each track relay R is a second relay designated by the reference character .Qjwith auexponent corresponding to the location and which exponent and connected I across the rails adjacent the entrance end relay, for purposes of explanation, 2 term a transmitting relay.

" Current is supplied to the various parts of the apparatus from a series of line transiorine rs each designated by the reference character s j with appropriate distinguishexponent and one of which is located adjacent the junction of eachtwo track'sec- -tions. primary 7 of each such .line

transformer-S is constantlysupplied with alternating current from some suitable source such as an alternator M over line wires 3-and 8.. r I

Referi-ing particularly to relay Q this relay is providedwith a circuit ivvhich passes -from secondary 6 of-transformer Sfi-through "wires 8and 9, back contact 10 of track rela -y PR, wire 11, back contact 12 of relay QF, wire lj3ywinding ofrelayu and wires 14, 15, 1'6 and IT back to "secondary 6 of transformer S. will be seen that this circuit is jcldsed lay Q is also' deenergi zed. Assuming that *relayRf defenei gized, current is supplied over the circuit j ufst traced to the w nding Toffrelay Q This relay thereupon becomes "en ergized. "The opening of backcontact 1'2 of reIay jQ opens itsown circuit'iand the relay thei'ezfore becomes tie-energized a 21111.

"closed relay Q is intermittently energized and operatesto open and close its contacts at a uniform rate. The control of e'achof the "remaining relays Q is similar to "that adjusted so that the times required forcomfplete cyclesof these relays are the sameffor all the relays". i i

rent to the section in therear in accordance ash tamecond t n i advance? particularly to section Li-B, firm?- fo'rmer' T 'for thissection is provided with two CiI'CllItSQ One of these circuits passes 'ltroin secondary 6 of line transformer S im 11 tvire17,front oint of contact is of relay Wire 19, bac contact of relay Q wires, 21 and 22, primary 5 of transforrne'r T and wires 23, 15 and 24. hack to l secondary 6 of transformer S This circuit is dosed o y w r ay B i e er ze and relay Q is deenergizeol. If, therefore, relay R is energized and relay vQ is con- Each relay Q controls the supply, -t

stinuously de energized, the circuit just i ;indicated diagrammatically at V.

current is supplied to the rails of section A-B, wherefore track relay R is energized. If, however, section A-B is occupied by a train so that relay R is de-energized, the closing of back contact 10 on this relay completes the operating circuit for relay Q which commences to oscillate. Still assuming track relay R to be energized, the circuit just tracedfor transformer T is closed cycle of relay Q and the rails of section A-B-are then supplied with current in the form of impulses of energy separated by.

time intervals. The current then supplied to the trackway I shall them the proceed code. Another circuit for transformer T may be traced from secondary 6 of transto section AB over back point of contact 26 of relay Q If however relay R is deenergized when relay B is de-energized the intermittent operation of relay Q closes the circuit for primary 5 of'transformerT for a brief interval at each extremity of the stroke of relay Q Section A-B is then supplied according to whatI shall term the caution code, with impulses of energy uniformly spaced apart and transmitted to the trackway at the rate of two impulses for each complete cycle of relay Q.

The operation of the apparatus associated with the remaining sections is similar to that just described in connection with section As shown in the drawing the section to the right of point C is occupied by a train Relay R is therefore de-energized but relay R is held in its energized condition by alternating current continuously supplied to the rails of section B-C by transformer T and the circuit for relay Q is therefore interrupted at back contact 10 of relay R Similarly, section 'AB is continuously supplied with alternating current over back contact 20 of relay Q which relay is continuously de-energized because its circuit is open at back contact 10 of relay R now energized.

I will now assume that a train Vmoves through the stretch of track shown in the drawing. 'As this train enters section A-B the de-energization of relay R completes the operating circuit for transmitting relay Q therefore supplied to section A-B. As the train enters section B-C the de-energization of relay R completes the operating circuit for transmitting relay Q -Relay R is de-energized however, and current is therefore supplied to the rails of section BC according to the caution code. It should be pointed out that the alternating current supplied to the track rails of any section is broken up into code impulse combinations only when that section is occupied by a train. only for a brief interval once during each 'A-B and BC, relay B. being de-ener- While the train is occupying both sections gized, current is supplied to section AB according to the caution code. lVhen the train moves out of section AB, relay R is no longer shunted and the first impulse transmitted to the trackway causes relay R to become energized. The opening of back contact 10 of relay R interrupts the circuit for relay Q and the latter relay is then continuously de-energized. Current is therefore supplied continuously to section A-B by transformer T over back point of contact 18 of relay R and relay R remains energized. hen the train passes out of section B-C relay R becomes energized so that current is then supplied to transformer T over front point of contact 18 of relay Ri, but this does not affect any of the other apparatus associated with section AB and relay R continues to be energized.

Referring now also to Fig. 2 the train carried governing mechanism comprises two magnetizable cores 27 and 27 located in advance of the forward axle 29 and disposed in inductive relation to the two track rails re spectively. Core 27is provided with a winding 28 and core 27* is provided with a similar winding 28*, the two windings 28 and 28" being connected in series so that the voltages induced therein by alternating currents flowing inopposite directions in the two track rails at any instant are additive. These two windings are connected, preferably through an-amplifier 30 and a rectifier 31, with a train carried relay designated by the referance character D, and which for purposes of explanation I will call the main relay. When the rails of' the stretch of track occupied by the train are being supplied with code impulse combinations. relay D will be energized. during each energy impulse and will be de-energized during the time interval between such impulses. Associated with main relay D are two slow releasing relays E and F. Each time relay D becomes energized an impulse of energy is supplied torelay E over a circuit which may be traced from a suitable source of energy such as a battery 3% through wires 35, 36, 37

and 38, front contact 39 of relay D, wire 40. winding of relay E and wires 41, 42, 43 and 44 back to battery 34. When relay E is energized a circuit is completed for relay F,

which circuit passes from battery 34, through wires 35, 36, 37 and;45,front contact 46 ofre'lay-E, wire-47, winding of relay F and wires-48, 42,43and 44, back to battery .34. It will be clear therefore thateach time relay Dbecomes energized, relays E and F both become energized. -When the main relay next becomes dcenergized the opening of back contact 39 thereon interruptsthe circuitforrelayE. 'Due to the slow releasing characteristic of'relay E a timeinterval elapse's between the jde-energiz ation of relay E andtlie openin'gofits front contact-46. At the expiration; of. this time interval the circuit for t relay F becomes opened and that relay, aftera similartime interval, reverses its contacts. Therelays'Eand F therefore operate incascade to measure the time interval elapsing between successive energizations of'relayD. y

RelayD also comprises an armature. 32 whichis arranged to close a transit contact 33 for a brief interval each time the armature 32:;Inoves from the position corresponding to theide-ene'rgized condition of relay D to theposit-ion corresponding to the energized condition o'fthis relay.

back contact 52 of slow releasing relay E,

wire 53, winding ofbridging relay J, and

will thereforefbe plainthat if relay E is open and relay'F is closed, relay J will receive a surge of energy each time transit contact 33 i's'closed. The circuit for relay K passes from battery 34,'through wires 35 and '36, transit contact 33 of relay D, wire 49,back contact 50 ofr-elay'F, wire 56, winding orrela K and wires :55, '43 and 44 back to battery 34.

:11, therefore, relay-F; is open, relayK will receive a surge of energy eachti1ne the transit contact 33 of relay D is closed.

In, explaining the operation of the apparatus as a whole. I will first assume thatthe train occupiesa stretch of track whicliis being-suppliedwith aproceed code,

as for example, section A.;B'of Fig. '1. Relay D is therefore energizedonce for each complete cycle of the transmittingrelay Each' time relay D becomesenergized,'the

'"clos'ing o'f'front contact 39 picks up relay E,

which in turn picks up relay F. When a lay D next becomes de-energized the opening of contact 39 interrupts thecircuit-for relay E but'relay F is then held in its energized condition over front contact 46 of elay After the expiration of the time interval required forthe release of 'rela'y E, contact 46opens and contact 52 of this relay closes. At the expiration of another time interval relay F releases. The parts are so proportioned that when the proceed code is being received the time between successive energizations of relay D is long enough for. both relays' E and F to release. Duringeach energization of relay D the transit contact 33 is closed fora brief interval, andsince' we haveseen that during the time interval be tween successive impulses supplied to relay D relays E and F both become released, it will be plain that relay F is open eachtime the transit contact 33 is closed, so that relay Kreceives an impulse of energy overback contact 505O of relay F and contact 33 for each impulse of the proceed code. Relay K is sufficiently slow releasing tobridge the time interval between successive energizations and the relay therefore maintains its front contact closed. It should be pointed out that because front contact 50- 50 of relay F is openwhen transit contact 33 is closed, relay J is not supplied with energy when the train is receiving a proceed code and thereforethis relay is open. Current therefore :flows from battery 34, through wires 35 and 57, back contact 58-58 of relayiJ, proceed'lamp 59, front contact 62-62= of relay K, and Wires 63 and 44 back to battery 34. Lamp 59 therefore is lighted and so indicates proceed. I will next assume that the stretch of track occupied by the train V is being supplied with the caution code. Under this condition relay D is energized twice for each complete cycle of the transmitting relay Q. During each energization of relay D, relays E and F both become energized :as explained inconnection with the proceed code, but the interval of. time between successive energizations of relay D isnow shorter than before. The. parts are so proportioned that during each time interval relay becomes released but relay F does not have time to release. Each time relay D becomes energized, therefore, the closing oftransit contact 33 supplies a surge of energy to relay J over front, contact 5050 of slow releasing relay F and back contact 52 of slow releasing relay E. Relay J is made sufliciently s ow releasing to bridge the time interval betweensuccessive surges of energy thus sup plied/[o it and so the relay maintainsiits front contact closed. Relay K, under these conditions, is deenergized, its circuit being open at back contact 50-50" of slow rcleasing relay F, and therefore a circuit is completed from battery 34, through wires 35 and57, front cOntaCt 58- 58 of relay J, caution lamp 60, back contact 697-62 of relay K, and Wires 63 and 44 back to battery 34. Lamp therefore becomes lighted to indicate caution. i It should be pointed out that shouldrelay (ill D become continuously energized or continuously de-energized, transit contact 33 would remain open and relays J and K would both be de-energizcd. Under these conditions current would flow from battery 34, through wires 35 and 57, back contact 5858 of relay J, lamp 61, back contact 6262 of relay K, and wires 63 and 44, back to battery 34. Lamp 61 would then be lighted to indicate stop. As shown in the drawing the parts are all in the positions corresponding to continuous energization of relay D. 7

Particular attention should be directed to the fact that with the apparatus illustrated in Fig. 2, the relays E and F, operating in cascade, are responsive to the time interval between the end of each impulse and an intermediate point in the following impulse. Since the relays E and F control the indicator lamps 59, and 61 in accordance with the length of this interval it may be said that the length of each such interval is measured by the relays.

In the modification of the train carried governing mechanism which is illustrated in Fig. 3 the main relay D is controlled in the same manner as explained in connection with Fig. 2. Associated with this relay is an auxiliary relay G. I will first assume that relay D is receiving the proceed code. The first energization of relay D completes a circuit for relay E from battery 34, through wires 35, 36 and 38. front contact 39 of relay D, wires 64 and 65, back contact 66 of relay G, wires 67 and 40, slow releasing relay E and wires 41, 68, 42, 43 and 44 back to battery 34. Energy supplied over this circuit energizes relay E, but as soon as the front contacts of relay E close current flows from battery 34, through wires 35, 36 and 38, front contact 39 of relay D, wires 64 and 69, winding of relay G, wire 70, front contact 71 of relay E and wires 72, 68, 42, 43 and 44 back to battery 34. Relay G immediately opens its back contact, thereby interrupting the circuit just traced for relay E. The energization of relay E completes the circuit for relay F over front contact 46 of relay E in the same manner as in Fig. 2.

It will be noticed that the closing of relay G de-energizes relay E and that the subsequent opening of contact 39 of relay D has no eficct upon the apparatus. When relay D is energized by the next impulse a circuit is closed for one of relays J or K depending upon the length of time between impulses. Assuming that relay D is receiving the proceed code, relays E and F both become de-cnergized during the interval between impulses. Then when contact 39 of relay D closes, current flows from battery 34, through wires 35, 36 and 38, front contact 39 of relay D, wires 64 and 65, back contact 66 of relay G, wires 67 and 49, back contact 5050" of relay F, wire 56, winding of relay K, and'wires 55, 43 and44, back to battery 34. The energization of relay D also again completes the circuit for relay E, and when this relay closes its front contact 71, relay G becomes energized, opening the circuit just traced for relay During the. time this circuit is closed, however, a surge of energy is delivered to relay K, and the relay becomes energized. As long therefore, as relay D receives the proceed, code, relay K receives a surge ofenergy for each energization of relay D, and relay K, being slow releasing,bridges the time interval between successive surges to hold its front contact closed. Lamp 59 is therefore lighted to display a proceed indication.

Similarly, if the relay D is receiving the caution code, the time interval between successive energizations of relays E and F permits relay E to open, but not relay F, and therefore each. time relay D closes its front contact a surge of energy is delivered to relay J from battery 34 over Wires 35, 36 and 38, front contact 39 of relayD, wires 64 and 65, back contact 66 of relay G, wires 67 and 49, front contact 50-50'of relay F, wire 51, back contact 52 of relay E, wire 53, winding of relay J, and wires 54, 55, 43 and 44 back tobattery 34. Relay J maintains its front contact closed during the interval between successive surges of energy supplied thereto, and lamp 60 is therefore lighted to indicate caution. Should relay D be continuously energized, as by the presence of uninterrupted alternating current in the rails occupied by the train, or should relay D be continuously deenergized, asby the absence of such current in the rails, relays J and K would both be'de-energized, and lamp 61 would be lighted to indicate stop.

It should be pointed out that with the apparatus here shown, the relays E and F, in cascade, measure the interval between a point in each impulse and the beginning of the next impulse. This feature has the advantage of being independent of the lengths of the impulses which may vary because of the reactance of the rails, or for other reasons.

Under some conditions it may be desirable to control the circuit of a slow releasing relay over its own back contact so that when energy is supplied tothis circuit, energizing the relay, the consequent'opening of the relays back contact will interrupt the relay circuit. I have discovered that under these conditions energy must be delivered to the relay after its back contact has opened to insure that the relay will be fullyenergized and that the relay will have its maximum period of retardation. It is, with this arrangement of circuits, desirable to supply a surge of energy to the relay after the operating circuit for the relay is opened by the wa Y 5 openingof its own back contact. In Fig. 4 I control the circuit for the slow releasing relay E over its own back contact 46 andl provide a transformer H for delivering asurge of energy to the relay after, its operate ing circuit is opened. This relay ischarged with energy during the time the operating circuit for the relay is closed, lVhen the relay circuit is opened, the energystored in the magnetic field about the transformer H is discharged into the relay, completingthe stroke of the relay, and energizing the rela to a degree which insures the proper retard ation time. I

The circuit for relay E passes fromybattery 34, Wires and 36, back point ofcontact 46 of relay E, wire 38,.front contact 39 "of relay D, wires 69 and 40, winding of. relay E, and wires 41, 70, 71, 42, 43 and 44 back to battery 34. Another circuit may be traced from battery34, through wires 35; and 36, back point of contact 46 of relay E, wire. 38, front contact 39 of relay D, wires 69. and 72, primary 73 of transformer H,: wires 71, 42, 43 and 44 back tobattery 34. It will, therefore, be seen that when relayE is de-energized and relay D is energized, current is suppliedto the winding of rela E and to the primary of transformer in parallel. i o y y In explaining the operation of theapparatus I will first assume that relay D is deenergized. Relay E is therefore de -energized. When relay D becomes energized current is supplied to primary 7 3,of transformer H and to the winding ofrelay as alreadyv explained. Relay Etherefore becomes energized and energy isstored in the magnetic field of transformer, H. When back contact 46 of relay E opens, the circuits for transformer H and relay E areo ened but front contact 76 of relay Eimmediately closes, completing a circuit from sec'ondar 74 of transformer H through wire 40,. win ing of relay E, wires 41v and Ti", front contact 7 6 of relay E, and wire 75 back to secondary 74 of transformer H, The energy which has previously been stored in, y the magnetic field of transformer H is therefore discharged into relay E, completing the .en: ergization of this relay and insuring that the relay will require its full retardation period to open its contacts. RelayF is controlled by relay E in exactly the same manner vas explained in connection with Fig. 2, itbeing noticed that no artificial means is required to complete the stroke of relay l because that relayis supplied with energy over. a front contact of relay E, which is ;closed for a comparativelylong time. y

, Relays J andK areselectivelycontrolled by the relays E and F in the samecgeneral way as. in Fig. 3, but apparatus also pro vided for insurmg that each ofthese relays i s fullyenergized by each a. surge of energy supplieclftheretol, y r o L Assuming that the relay D is receit in gf the caution code, relay will becomes, energized durin each time interval; between successive energizations of "relay D, but re-l lay F will not become dc-energized,"during such time intervals. Each timefniontf con: tact 39- of relay, D closes, a .oircuitf is CIQSGTL from battery '34, through wires iio and 36, back pointofcontact 46 ofrela! E, wire, 38, front contact 39 of'relay D, w1res 69, 72. and} 49,". front Contact 50 50 [ofrelay F, Wire 511,,back contact52 of relay E,wires 53, 7 8 and 79, winding of relayJ, and Wires 54, 91, 55,43 and144 back to battery. The circuit just traced isiprovided with a branch which asses from" Wire 53, through back c011 tact 8 of'relay E, wire 81, primary 82 of. a transformer and wires 88 and 84, back to wire 91. It will'thereforebe seen'that when relay E is it (ls-energized, primary 82 of transformer P is connected in parallel with relay J. i e 1 Secondary86 of transformer is con nected with relay J throu h an. asymmetric cellfN that is,a cell having the characteristic of offering a higherresistance to cur rent flowingthrfoughfthe cell in one direction than to current'fiowing in the opposite direction. The circuit including the cellN passesjfrom one terminal of secondary 86 of transformer P through asymmetric cell N, wire 79, winding offrelay J, and wires 54, 84 and 87. back tosecondary 86 oftrans former P The arts. are so arranged, that when current is ing supplied to relay J and rimary 82 oftransformer P ove'rthe circuits,includingfront Contact 39 of relay D, the asymmetric cell-N? prevents the How of current through secondary 86 of trans former 1:" whichcurrent would be of such direction as to oppose the current in relay 'J. Energyfis therefore stored in the trans] former field. When relay E becomesener gized, thehcircuits forrelay J andprimary 82 are interrupted. The ener stored in the transformer P is then supplied to relay J the current being of such direction that the asymmetric cell offers only a sliglit'opposition to such current. The stored energy supplied to relay J from transformer P completes the stroke of relay J and insures the full retardation timeof the relay. A transformer P and asymmetric cellN asso iated with relay Koperate in the same manner as explained in connection with the similar parts associated with relay J Lamps. '59, '60 .and61 are controlled relays J and Kinsexplained inconnection witn Fig. 2.

relay E;is proyidedwith two windings and. 90. Winding .89 is constantly connected lie In the mama-seen illustrated iii Fig 5 v with secondary 74 of transformer H. The circuit for winding 90 of relay E passes from battery 34, through wires 35, 36 and 88, back point of contact 46 of relay E, wire 38, front contact 39 of relay D, wire 40, winding 90 of relay E, and wires 41, 71, 42, 43 and 44 back to batter 34. The circuit for primary 73 of trans ormer H may be traced from battery 34, through wires 35 and 36, back contact 91 of relay E, wire 91, front contact 93 of relay D, wire 69, primary 73 of transformer H, and wires 71", 71, 42, 43 and 44 back to battery 34. It will therefore be seen that if relay E is de-energized and relay D becomes energized current is supplied to primary 73 of transformer H and also to winding 90 of relay E. The parts are so arranged that the current supplied to winding 89 of relay E b secondary 74 of transformer H during the rst surge of current to primary 73 of transformer H opposes the current in winding 90 of relay E and prevents the operation of this relay until the current values have become steady. When the field of transformer H has been built up to its maximum value the current delivered to Winding89 by secondary 74 is, of course, zero and the current then supplied to winding 90 of relay E causes the relay to operate its contacts. \Vhen back contact 46 and 91 of relay E open, the supply of current to primar 73 of transformer H and to winding 90 o relay E is discontinued. The decay of the magnetic field of the transformer H supplies energy to winding 89 of relay E which completes the stroke of the relay and insuresthe normal retardation period of this relay. Relay F is controlledby relayE in the same manner asv explained in connection with Fig. 2.

, Relays J and K are each provided with a transformer P as in Fig. 4. The secondaries of these transformers are controlled by contacts on the associated slow releasing relays instead of b asymmetric cells N. For ex ample'I wil assume that relay E is de-energized and relay F is energized as when the caution code is being received, and that relay D closes its front contact 39. During the time interval prior to the opening of the back contacts of relay E a surge of energy is supplied to relay J over a circuit which passes from battery 34 through wires 35, 36 and 88, backpoint of contact 46 of relay E, wire 38, front contact 39 of relay D, wires 40 and 78, front contact 5O50 of relay F, wire 51, back contactv 52 of relay E, wires 53 and 79, winding of relay J, and wires 54,

91, 55, 43 and 44 back to battery 34. A branch is provided for this circuit from wire 7 53, through back contact 8080 of relay E, primary 82 of transformer P and wires 83 and 84, back to wire 91. It will thereforehe plain that during this brief time interval during which current is supplied to relay J, a surge of energy is also supplied to primary 82 of transformer P When rela E becomes energized the circuit just trace for relay J is opened and the circuit through primary 82 of transformer P is also opened, but the closing of front contact 80 of relay E completes a circuit from secondary 86 of transformer P through wire 81, front contact 80--80 'of relay E, wire 79, winding of relay J, wires 54, 84 and 87 back to secondar 86 of transformer P. The energy store in the magnetic field of transformer. P is therefore discharged through the circuit just traced and completes the stroke of relay J and insures the maximum retardation period of this rela The operation of transformer P associated with relay K will be readily understood from the foregoing without further ex lanation.

It Wlll be seen that with the apparatus shown in Figs. 4 and 5, the relays E'and F, operating in cascade, measure the'time inter val between an intermediate point in each impulse and the beginning of the next impulse. I

Referring now to Fig. 6, the apparatus is similar to that shown in Fig. 2 with the exception that a third slow releasingrelay L, which I shall call a checking relay, is 9 associated with relays E and F. Relay L is energized only when relay F is energized, the circuit for the checking relay passing from battery' 34, through wires 35, 36, 37 and 93, front contact 94 of relay F, wire 95, winding of relay L, and wires 96, 42,43 and 44, back to battery 34. j

The front contact 98 of the checking relay L is connected, by means of Wires 97 and 99, between the transit contact 33 and contact 50 of relay F., r i V I Relays J and K are controlled by relays E and F as already described in connection with Fig. 2, but it should be noticed that neither of these relays can he energizedwhen relay L is de-energized.

With the apparatus shown in Fig. 2, should relay F stick in its energized condition, while the proceed code is being'received, relay J would be energized so that lamp 60 would be lighted instead of lamp 61.

With the apparatus shown in Fig. 6, this can not occur, for should relay F stick in its de-energized position, the checking relay L would remain in its de-energized condition, even though relay E should become energized. Re ays J and K would therefore both remain de-energized, and lamp 61 wou1d be lighted, no matter what code were being received by relay D.

Furthermore, should the time interval between successive energizations of relay D be considerably longer than the time interval corresponding to the proceed code,-relay L would become de-energized after each such nemm energization and before relay 1) would be re-energized b the succeeding *impiilse. Relays J and therefore could not' hecome energized "by the closing of "contact 33. It follows that -a stray code current, "having impulses separated .by time intervals longer than the intervals of theproceed code-could have no effect upon theapparatus.

. F or purposes o'f explanation l' have shown the checking relay L applied to theapparaltllS shown in Fig. 2, but it should be clearly pointed out that anyo'f the other views could be "similarly modified.

Although I have herein shown and described only a few forms of railwaytraflic controlling apparatus embodying my invention, it 'is understood that various changes and modifications may be'made therein "within the scope of the appended claims without departing from the spirit and scope'of my invention. y

Having thus described my inventiomwhat 'I claim is: l.

1. In combination, a stretch of railway track, means for suppl ing said stretch with energy in the form o a series of impulses each separated from the preceding impulse by a time interval, and governing means selectively responsive to the time intervalibetween a givenpoint in each such impulse and a different-point in the following impulse.

V 2.1n combination, a stretchfo'f railway track, means for supplying said stretch with energy in the form of a series of impulses each separated fronrthe preceding impulse .bya time interval, and governing means selectively"responsive to the time interval between an intermediate point in each said impulse and the beginning of the following 7 impulse. l

3. In. combination, a sourceolf .code impulse combinations [each comprising an energy impulse and a time -interval of mo energy, a relay receiving energy from" said -sourceand :arrangedto be energized bysaid impulses but to be de-energizedrduring said time intervals, and slow releasing relays for .nieasuringwthe time .frompa point ineeach said impulse sto atdifferent point Iinwthe next said impulse.

4. In combination, a" sourcesof code .im-

,pulse (combinations each comprising an 3 en+ ergy impulse landca time interval of no -energy,a pl1 1rality of slow releasing relays,

means "for energizing .allsaid relays dur ng each said iimpulse but for successively de- {energizing said relays during each said time interval, and governing means controlled jointly by said slow .releasing relays. v y

:5, In combination, a main elay, means :t'or intermittently energizing said main relay, two slow releasing relays; gmeans for energizing both said slow releasing relays when said main ibecomes energizedfi said slow releasing relays successively be- "cumin de-energized 'w h'en said maimrelaytbe- :eomese-energized, and governing meanscontrolled jointly by said slow releasing 'wrelays.

6. In combination, a main relay, means for intermittently"energizing said main relay, a plurality of slow u'eleasing :relays, means for energizing all said slow releasing relays when said :main relay :becomes eneregized, said slow releasing relays successively becoming de-energized when said main relay becomes de energized, and governing means controlled jointly by said slow releasing relays and lay-said main relay.

7."In'co1nbinati0n, a main relay, means for intermittently energizing said inain rela-y, a finst slow releasing relay having a circuit including a contact of said main reilayya second slow releasing relay having a circuit including a front 'contactof said first slow releasing relay, and governing "means controlle d ointly by said two slow releasing relays.

8. In combination, *a source of codeimpulse combinations each comprising an energy impulse and a "time interval of no current, :two slmwreleasing'relays, means for energizing both said relays duringcach such ll'l'lljll'lSB but iior successively (le-energizing said 'relays during each said time interval, and 'governing means selectively responsive to the length of time 'elapsing between successive energizations of said relays.

FQQ In combination a main relay, means for intermittently energizing said main reday, slow releas'ing relays controlled in -cascade' for measuring the time intervals between successive energ'ization of said main relay, and governing means selectively controlled lby said slow releasing relays in accordance with the lengths of said time in- *tervals.

In combination, {a main relay, means for intermittently energizing said main relay,*two bridging relays slow acting "relays controlled by said main relay for selectively operating said hridging relays in accordance with the time intervals between successive energizations of said main relay, and governing means s bridging relays.

electively controlled by said relay,a circuit for said relay including two contacts, means for intermittently closing jone of said contacts means controlled by saidfirst slow releasing relay for opening ;the remaining said contact, a secondslow releasing relay controlled by saidfirst slow releasing relay andgoverning meansselectively controlled bysaidtwo slow releasing relays. i

12. In combination, a main relay, means forkintermittently energizing said 'main relay; 'affirst slow releasing 'relay,-means for supplyin' said first slow releasing relay with :energy hen said fmain relay {bece'mes emurs Ill Fill

gized, means controlled by said firstslow releasing relay for subsequently interrupting such supply independently of said main relay, a second slow releasing relay controlled in cascade by said first slow releasing relay, and governing means selectively controlled by said two slow releasing relays in accordance with the time interval between successaid slow releasing relay for measuring the time interval between successive energizations of said main relay, and governing .means selectively controlled by such time measuring means.

14. In combination, a main relay,'means -for intermittently energizing said main relay, a slow releasing relay, a circuit including a front contact of said main relay for initiating operation of said relay, means controlled by said main relayfor interrupting said circuit, means independent of said circuit for completing the operation of said relay, means including said slow releasing relay for measuring the time interval .between successive energizations of said main relay, and governing means selectively controlled by said time measuring means.

15. In combination, a main relay, means for intermittently energizing said main relay, a slow releasing relay, a circuit including a front contact of said main relay for initiating operation of said relay, means controlled by said main relay for interrupting said circuit, means for storing energy while said circuit isclosed and arranged to discharge such stored energy into said slow releasing relay to complete the operation of said relay after said circuit is interrupted, and governing means controlled by said slow releasing relay. i a 16. In combination, a' main relay, means for intermittently energizing said mainrelay, a slow releasing relay, a circuit for said slow releasing relay including its own back contact and a front contact of said main relay, a transformer having a primary connected in parallel with said relay, a second ary onsaid transformer, and means for conmeetin said secondary with said slow releasing relay immediately after said circuit is broken.

plying energy to said slow releasingrelay when said main relay is energized, means controlled by said slow releasing relay for from the source, and governing means controlled by said relay.

19. In combination, a contact arranged to be operated periodically, a relay, a source of energy, means for connecting said relay with said source during each operation of said contact, a transformer'having a secondary connected in parallel with said relay, an asymmetric cell connected in series with said secondary. and means for supplying energy to the rimary of said transformer when energy is being supplied to said relay over said contact. 1

20. In combination, a relay, a transformer having a secondary connected in parallel with said rela means for su plying direct current to sai relay and to t e primary of said transformer, an asymmetric cell in series with said secondary to prevent flow of current through said secondary due to the growth of the magnetic field of said transformer, but permitting the energy "stored in said field to be discharged into said relay, and governing means controlled by said relay.

21. In combination, a main relay, means for intermittently energizing said main relay, aslow releasing relay, means for supplying said slow releasing relay with energy when said main relay becomes energized, means controlled by said slow releasing relay for subsequently interrupting such supply independently of said main relay, and governing means select-ively'controlled by said slow releasing relay in accordance with the time interval between successive energizations of said main relay. r

22. In combination, acontact mechanism arranged to be intermittently operated, a relay, a circuit for said relay closed fora.

brief interval during each operation of said mechanism, a, transformer having a primary arranged'to be connected in parallel with said relay when said circuit is closed,'means for connecting the secondary of said transformer with said relay immediately after said circuit is opened, and governing means controlled by said relay. V

In testimony whereof I 'aflix my signature.

, HER-BERT A, WALLACE. 

